Concern over human impact on climate change prompted a 1997 United Nations conference in Kyoto, Japan. The resulting Kyoto Protocol seeks to stabilize greenhouse gases in the atmosphere “at a level that would prevent dangerous anthropogenic interference with the climate system.”
Perfluorocarbon compounds (PFC's), hydrofluorocarbon compounds (HFC's), chlorofluorocarbons (CFC's), hydrochlorofluorocarbon compounds (HCFC's), and their like, have been widely used in a broad variety of industrial, commercial, consumer and public use applications and uses. Recently, concern has increased about potential damage to the earth's atmosphere and climate, and certain perfluorocarbon compounds (PFC's), hydrofluorocarbon compounds (HFC's), chlorofluorocarbons (CFC's), hydrochlorofluorocarbon compounds (HCFC's), and their like, have been identified as particularly problematic in this regard, at least in part because of the greenhouse gas effect and relatively high global warming potentials (GWP) associated with those compounds. In view of the relatively high GWP of these compounds there has been a vigorous search for alternative compounds of lower GWP to replace these compounds of higher GWP in those use, application and compositions to be used in such applications and uses.
The entry into force of the Kyoto Protocol on Feb. 16, 2005 has accelerated the need for elimination or greatly reducing the use of GWP compositions. Thus, there is a continual search for new fluorocarbon and hydrofluorocarbon fluids for use, especially in air conditioning and refrigeration uses, so as to reduce global warming and for lessening possible depletion of the ozone layer.
One of the key ingredients in the search for such new low global warming potential (GWP) candidates is trifluoroiodomethane (CF3I). In such the compositions there is often or usually present a lubricant. Any of a variety of conventional lubricants may be used. An important requirement for the lubricant is that, when in use in a refrigerant system, there must be sufficient lubricant returning to the compressor of the system such that the compressor is lubricated. Thus, suitability of a lubricant for any given system is determined partly by the refrigerant/lubricant characteristics and partly by the characteristics of the system in which it is intended to be used. Examples of suitable lubricants include mineral oil, alkyl benzenes, polyol esters, including polyalkylene glycols, PAG oil, and the like. However, it has been discovered that these lubricants, which are hydrogen bearing for the most part, by interaction with trifluoroiodomethane results in the production of highly undesirable trifluoromethane (HFC-23) which has a high GWP. This HFC-23 breakdown product is very undesirable in a product or composition that is intended to have and should have a low GWP. Thus, there is a need to be able to remove HFC-23 from such products or compositions, whether the HFC-23 is present as a breakdown product or as an undesirable component initially present in the product or composition. While there have been a number of processes proposed for the separation of HFC-23 from product or compositions with other lesser GWP compounds, most of these methods are expensive and inefficient. Thus, there is a need for an effective, efficient and simple way to remove HFC-23 from such products or compositions.